According to EP 265 699 fats with a superior digestibility and absorptivity are obtained, when these fats are composed of triglycerides having a specific amount of C8 to C14 fatty acid residues at the 2-position, while residues with C18 or higher fatty acids are bonded at the 1.3-positions. Typical examples of the C18 and higher fatty acids are polyunsaturated fatty acids, such as arachidonic acid, eicosapentenoic acid and dodecahexenoic acid. However nothing is disclosed about fat compositions that combine in the fat saturated fatty acid residues and at least two different long chain polyunsaturated fatty acid residues. In WO 90/04012 it is disclosed that triglycerides that contain saturated C8/C10 fatty acid residues in 1.3 and simultaneously a polyunsaturated fatty acid residue (in particular DHA) in the 2-position, have beneficial nutritional properties, in particular for enteral or parenteral purposes. However again, nothing is disclosed about fat compositions that contain in the fat specific amounts of saturated and two different polyunsaturated fatty acid residues.
From WO 94/00044 it is known that fatblends that contain unhardened fish oil have significant health benefits. Fish oil often contains appreciable amounts of two different polyunsaturated fatty acids, e.g. DHA and EPA. However it is also known that fish oil has a number of draw backs, such as a low oxidative stability (e.g. noticed as off taste during storage at ambient temperature). Further fish oils do not have structuring properties, which makes it difficult to apply them in fat compositions wherein a structuring agent is required in order to give the fat composition a performance, that is desired to make the fat applicable in foodproducts.
From Endo c.s in Bioscience Biotechn. Biochem. 57 (12) 1993 pages 2202-2024 it is known, that incorporation of myristic acid groups into sardine oil leads to a product with a slightly improved oxidation rate, whereas incorporation of stearic acid in the sardine oil hardly had any effect on the oxidation rate. This incorporation of saturated fatty acid is performed by an enzymic process, applying Candida cylindracea or lypozyme as an enzyme. It is taught that starting from sardine oil with about 8% DHA and 12% EPA, products are obtained with a decreased amount of total long chain polyunsaturated fatty acids (about 11% if C14:0 was incorporated and about 17.5% if stearic acid was incorporated).
Therefore, above document does not disclose triglycerides that contain at least 20 wt % of a most abundant long chain polyunsaturated fatty acid in combination with at least 2% of saturated C2-C12 or C20-C24 fatty acids.
U.S. Pat. No. 5,151,291 discloses triglycerides that are rich in EPA and that also contain xe2x80x9chigher fatty acid residuesxe2x80x9d. The higher fatty acid residues are defined as saturated fatty acid with at least 14 C-atoms, but also DHA could be considered as such. The products obtained must combine a high EPA level with a high melting point in order to make them suitable as margarine fat. Because of above requirements the triglyceride products never will combine levels of a most abundant long chain polyunsaturated fatty acid of more than 20% with the presence of a second most abundant long chain polyunsaturated fatty acid in a ratio between these two LCPUFA""s of more than 2, while also at least 2% saturated C2-C12 or C20-C24 fatty acid will be present in these triglycerides.
We have performed a study to find out, whether fat compositions existed, that could overcome the draw backs of the known fat compositions, while they would retain the beneficial effects of the presence of relatively high amounts of polyunsaturated fatty acids. This study has resulted in the finding of novel fats, that combine the following beneficial product properties:
our novel fats display better oxidative stability than triglycerides with similar compositions, however not having our levels of saturated fatty acids present;
our novel fats are better for the development of the brain, in particular when consumed by infants. This effect is due to the relatively high levels of dodecahexenoic acid (DHA) in our fats;
our novel fats also can contain relatively high levels of eicosapentenoic acid (EPA), which makes our fats healthier, due to the effect of EPA on coronary diseases;
our novel fats display a lower calorific behaviour. This is due to the presence of the short chain saturated fatty acid, which will decrease the molecular weight of our fats and thereby will decrease simultaneously its caloric contents. Fats, that contain long chain saturated fatty acids, such as behenic acid, display a reduced fat absorption by the body and thus display a decreased digestibility;
our novel fats display better structuring properties than fats without the saturated fatty acids;
our novel fats can be obtained as a result of interesterification reactions, in particular enzymic interesterification,.which results in fats with a better triglyceride-distribution than known fats. Simultaneously these fats will display an improved melting behaviour as our fats will hardly contain any trisaturated triglycerides.
our interesterified fats will also give better digestion of polyunsaturated fatty acids because, as a result of the interesterification with short or medium chain fatty acids tripolyunsaturated triglycerides will be hardly present in our fats.
So our inventions concerns with novel fats, that display one or more of above beneficial effects. Our novel fats can be described as a triglyceride-composition, comprising at least two long chain poly-unsaturated fatty acids L1 and L2, both having at least 3 unsaturations and having at least 20 carbon atoms from which L1 is the most abundant and L2 is the second most abundant, wherein the triglyceride composition contains at least 20 wt % of L1, while the weight ratio L1:L2 is at least 2, and the triglyceride composition also contains at least 2 wt % preferably at least 5 wt %, more preferably at least 15 wt %, most preferably at least 30 wt % of saturated fatty acids with 2-12 and/or 20-24 carbon atoms, whereas the triglyceride composition does not contain more than 10 wt % of saturated fatty acids with 16-18 carbon atoms, while at least 5 wt % of the saturated C2-C12 or C20-C24 fatty acid residues is bonded on a triglyceride molecule, wherein at least L1 and/or L2 is present.
Preferred fats are triglyceride compositions wherein the amount of L1 is more than 30 wt %, while the weight ratio L1:L2 is at least 3, while triglyceride compositions wherein the amount of L1 is at least 40 wt % and the weight ratio of L1:L2 is at least 3.5 are even more preferred.
The most preferred C2-C12 saturated fatty acids are acetic acid, butyric acid, octanoic acid, and lauric acid. It was found, that fats with relatively low levels of C16-C18 saturated fatty acids could be obtained. Advantageously the level of C16-C18 saturated fatty acids is less than 8 wt %, in particular less than 5 wt %.
The most abundant polyunsaturated fatty acid L, is preferably DHA (=C22:6). The second most abundant polyunsaturated fatty acid advantageously is EPA (C20:5). Very useful triglycerides are obtained, when L1=EPA and L2=DHA.
We found that the best oxidative stability was obtained, if at least 5 wt %, preferably at least 10 wt %, most preferably at least 20 wt % of the saturated C2-C12 or C20-C24 fatty acid residues is bonded on a triglyceride molecule, wherein at least L1 and/or L2 is present.
Our triglycerides can be applied as such in foodproducts, however it can also be very suitable to blend our novel fats first, before applying them. Therefore part of our invention is also a blend of triglycerides, comprising 0.3-95 wt % of the triglyceride according to the invention, and 99.7-5 wt % of a complementary fat, having a solid fat index at 10xc2x0 C. (N10) that is either, at least 5% more, or at least 5% less than the N10 of the triglycerides according to the invention.
Above blends suitably can be composed of 5-80 wt %, in particular 20-70 wt % of the triglycerides according to the invention, and 95-20 wt %, in particular 80-30 wt % of the complementary fat.
Many types of complementary fat could be applied. However we prefer to use complementary fats having a solid fat content (NMR-pulse; not stabilized) of more than 15 at 20xc2x0 C., preferably more than 20. The N-values were measured on fats subjected to the following T-regime: 5 minutes at 60xc2x0 C., 60 minutes at 0xc2x0 C. and 30 minutes at the measuring temperature.
Very useful complementary fats for our blends can be selected from cocoa butter equivalents, cocoa butter, palm oil or fractions thereof, palmkernel oil or fractions thereof, interesterified mixtures of above fats or fractions or hardened components thereof, or from liquid oil, such as sunflower oil, high oleic sunflower oil, soyabean oil, rapeseed oil, cottonseed oil, safflower oil, high oleic safflower oil, maize oil, MCT oils or fish oils.
The blends so obtained display a solid fat content (NMR-pulse; not stabilized) of 0-85, preferably 10-70, most preferably 20-60 at 5xc2x0 C. and less than 30, preferably less than 20, most preferably less than 5 at 35xc2x0 C.
Although our fats already have an improved oxidative stability, we found that this stability can be further improved when our blends contain an effective amount of an oxidation stabilizer, selected from the group consisting of: natural or synthetic tocopherols, other natural anti-oxidants, BHT, BHA, free radical scavengers, enzymes with anti-oxidant properties.
Effective amounts can range from 100 ppm to 5 wt % (on fat).
Part of our invention are also the foodproducts, comprising a fat phase, such as spreads, margarine, cream alternative, infant food, chocolate, confectionery, bakery products, sauces, ice-creams, ice-cream coatings, cheese, soups, mayonnaise, dressings, enteral or parental products, wherein the fat phase contains a fat as described above.
Our fats can be obtained by preparing the pure triglycerides and blending these in the required ratios. However a very useful method for the preparation of our blends is an interesterification of a (non-hardened) fish oil with a saturated fatty acid. This interesterification can be performed by using an enzyme. In that case enzymes can be applied, that display a specificity for e.g. long chain polyunsaturated fatty acids over saturated fatty acids, or that display a preference for one long chain polyunsaturated fatty acid over another long chain polyunsaturated fatty acid.
In our example I we have set out another possible interesterification method for the preparation of our novel fats. According to this method a fish oil is first subjected to a glycerolysis in the presence of a lipase. The crude reaction product obtained is enriched in long chain polyunsaturated fatty acids. This crude product is reconverted to triglycerides by performing an interesterification, using a fat high in saturated fatty acids.
Other methods to prepare our novel fats are illustrated by our other examples.
wf(TUNA)f=TUNAf=The olein fraction of semi refined tuna oil obtained by low temperature solvent fractionation, having at least 35% of DHA.
(BOO)s=The stearin fraction of an enzymic interesterified blend of high oleic sunflower oil and behenic acid.
fhPO=Fully hardened palm oil.
CCB=Cocoa butter.
POf37=Partially hardened palm oil olein fraction melting point of 37xc2x0 C.
CN=Coconut oil.
CNs=Coconut oil stearin fraction.
nPOm=Wet fractionated palm oil mid fraction.
df(PO)f=Dry fractionated palm oil olein fraction.
HS1=Hardstock=The stearin fraction of a chemical interesterrified blend of fully hardened palm oil and a fully hardened palm kernel olein fraction.
SF=Sunflower oil.
PO=Palm oil.
in=Interesterified.